1. Field of the Invention
This invention relates generally to electronic devices, and more particularly to heat spreaders for providing thermal management of electronic devices, including semiconductor chips.
2. Description of the Related Art
Handheld computing devices, such as smart phones, tablet computers and e-book readers, present significant thermal management challenges. There is ongoing user demand for devices that are not only smaller form factor for greater portability but also powerful enough to handle video and other computing intensive tasks. The provision for significant computing power in a relatively small form device often translates into the need for significant thermal management of the heat dissipating devices.
One common solution used to transfer heat from a processor in a small form device includes the use of a heat spreader that is in thermal contact with the processor. The heat spreader is in turn, in thermal contact with a heat exchanger via a heat pipe or other structure. The heat exchanger often includes an air mover such as a fan. One example of such a conventional device is the model LE1700 manufactured by Motion Computing, Inc. The LE1700 includes a very thin fan connected thermally to a heat spreader mounted to the microprocessor and by way of a heat pipe. The fan vents air to the external ambient by way of a small vent. An Acer model Iconia is another conventional example.
Even with the conventional thermal management system just described in place, hot spots on the surface of the computing device that contact the user can arise due to direct conductive thermal pathways between heat dissipating components inside the device and the exterior wall of the device housing. Not only does a typical handheld microprocessor dissipate heat, but other components as well, such as hard drives, power supply units, batteries and others. Indeed, the problem of heat dissipation is often exacerbated during times when the computing device is connected to an external AC power source to recharge the battery.
Another potential pitfall associated with the conventional thermal management system just described is the issue of both acoustic and electrical noise associated with a cooling fan. Such issues can be reduced though not completely eliminated through the use of appropriate noise filtering circuitry and fan and vent design. However, there remains the issue of power consumption to run the fan.
The present invention is directed to overcoming or reducing the effects of one or more of the foregoing disadvantages.